Shark numbers higher
than in most of Caribbean

27 May, 2019

This year marks the 10th
anniversary of a fruitful partnership between the Department of
Environment (DoE) and UK-based Marine Conservation International
(MCI) aimed at gathering information on and protecting sharks in
Cayman waters.

The partnership led to
the creation of the Shark Conservation Cayman programme (initially
called Cayman Islands Large Marine Predator Programme), which helped
push for the complete protection of elasmobranchs, such as sharks and
rays, under the Cayman Islands National Conservation Law (NCL). The
protections took effect in April 2015 making it illegal to fish for
sharks and stingrays in Cayman waters.

Although the NCL
protections are relatively recent, thus making it difficult to gauge
their overall impact, the shark conservation partnership has
documented some encouraging data for these apex marine predators.

“Our data suggest the
overall abundance of sharks in Cayman Islands’ waters is currently
higher than in most of the Caribbean,” said MCI Co-Director, Mauvis
Gore, a professor at Heriot-Watt University in Edinburgh. “However,
the numbers are not quite as high as in a few places – such as
Bahamas and Belize – where sharks have been protected for longer
periods.”

Large-bodied sharks, such
as reef sharks, nurse sharks, hammerheads and tiger sharks – all of
which are found in Cayman’s coastal waters – have significant
value, according to Prof. Gore. The non-consumptive tourism value of
local shark species estimated by the project was between US$46
million and US$63 million. Scientists also theorise that sharks, as
top marine predators, can help protect coral reefs via a “cascade”
effect within the food chain.

“Simply put, sharks
will eat a certain number of mid-level predators that feed on
smaller, herbivorous reef fish. This, in turn, regulates the number
of fish that eat algae from reef areas, keeping them clear for coral
growth,” said DoE-MCI Shark Project Officer Johanna Kohler. “We
believe there is a correlation between a healthy shark population and
healthier coral reefs.

“Sharks do not ‘steal’
marine stocks from local fishers,” Ms. Kohler said. “Rather,
we’ve observed they tend to bolster the numbers and health of reef
fish by protecting them from mid-level predators and also by weeding
out some less successful specimens, keeping the weaker ones from
reproducing.”

Ms. Kohler, a PhD student
from Germany, has partnered with DoE and MCI scientists for the last
three years in Cayman, performing the biannual shark surveys using
Baited Remote Underwater Video cameras, a non-invasive
technology that allows scientists to record the sharks in their
natural environment without the animals having to interact with
humans. Shark Conservation Cayman has also placed tracking devices on
more than 50 local sharks over the past 10 years, allowing scientists
to track their movements via acoustic monitoring.

The tracking data
available tends to show that many Caribbean shark species have a
range of more than 10 kilometres. “This suggests that, to be
provided with adequate protection, shark species require marine
protected areas on the scale of Cayman’s recent marine parks
enhancement to be put in place throughout the Caribbean,” Prof.
Gore said.     

To form Shark
Conservation Cayman, the DoE combines its marine and staff resources
in conjunction with MCI’s scientific expertise and the
participation of graduate-level students, such as Ms. Kohler, to do
more than either organisation would achieve on its own.

“When we started the
shark project 10 years ago, the DoE identified this area as one where
we needed to improve our scientific data collection and research,”
DoE Director Gina Ebanks-Petrie said. “Now, thanks to this
partnership, we have much better information available to help
protect these ecologically and economically important predators.

“To some extent, the
attitude in Cayman toward sharks has changed over the past decade.
Shark Conservation Cayman has spent a lot of time in local classrooms
and talking to local fishermen about these crucial marine species,”
Ms. Ebanks-Petrie said. “Ten years ago, the prevalent view of
sharks was ‘if you see one, kill it.’ I believe that people today
have a better understanding of why sharks are important to us.”

In addition to DoE and
MCI staff time and resources, Shark Conservation Cayman has been the
recipient of three Darwin Initiative grants from the U.K. Department
for Environment, Food and Rural Affairs (Defra). It has also received
generous donations from local brewery Caybrew via its aptly named
‘White Tip’ brand, a brand which supports shark conservation
developed collaboratively with DoE and MCI. In addition, other
sponsors include the Save our Seas Foundation, Fosters Food Fair, the
Southern Cross Resort and Ocean Frontiers.

Project collaborators in
the scientific community include Dr. Edd Brooks (Cape Eleuthera
Institute), Prof. John Turner (Bangor University), Prof. Callum
Roberts (University of York), Dr. Mahmood Shivji (Nova SE University)
and Dr. Guy Harvey (Guy Harvey Research Institute).

“We’d like to thank
all our partners in this effort and hope to receive their continued
support over the next ten years,” Professor Gore said.

“There is still so much
we don’t know for certain about sharks in our waters,” said Ms.
Ebanks-Petrie. “We believe more time and diligent study on this
project will provide more valuable insights.”

Minister for Environment,
the Hon. Dwayne Seymour, is pleased with the ongoing project: “I
would like to take this opportunity to express my appreciation for
the sustained efforts of the DoE team and their affiliates, for the
protection of this important species.”

If you want to learn more
about DoE/MCI shark conservation research please see following link
to the DoE website:
http://doe.ky/wp-content/uploads/2017/10/Ormond-et-al-2017-Protecting-Cayman-Island-Sharks-GCFI-69-7.pdf.
You may also wish to check out the Sharks & Cetaceans page on
Facebook, which is updated regularly, or contact DoE Public Education
and Outreach Officer Brent Fuller via phone at 244-5984/922-5514 or
on email brent.fuller@gov.ky.

IMAGES:

Photo captions: (credit
DoE/MCI)

Photo 1 – Six Caribbean
reef sharks are shown here in one frame taken from a DoE/MCI survey
in Little Cayman during 2017.

Photo
2 – DoE/MCI Shark Project Officer Johanna Kohler, assisted by DoE’s
Mike Guderian, places an acoustic tag on a shark during a recent
research survey.

Photo 3 – In this photo
from 2010, DoE research officers Janice Blumenthal and James Gibb
look on as members of the Marine Conservation International/DoE team,
including Professor Mauvis Gore (centre), place an acoustic tag on a
shark.